Field of the invention
The present invention relates to a system for actuating an electrical valve from a remote location utilizing a battery to provide power to actuate the valve. A supervisory circuit loop including a capacitor and inductor therein is provided for receiving a signal indicative of a desire to close the valve. The use of the capacitor as the supervisory element in the supervisory circuit loop minimizes current drain and allows the battery to continuously energize the supervisory circuit loop and still have enough energy to actuate the valve after many years of use. An energy storage means is provided and is charged from the battery by a charging circuit when the supervisory circuit loop senses a signal indicative of a desire to close the valve. A feedback circuit is provided to feedback to the supervisory circuit loop a signal indicative of valve actuation.
Circuits for actuating an electrical valve from a remote location are known in the art. In many of the known systems line potential is utilized to actuate a solenoid valve. However, when it is desired to use a battery rather than line potential it is imperative to minimize battery drain to provide for long system life. The Cah U.S. Pat. No. 4,469,304 discloses a pulse actuated solenoid valve which utilizes a capacitor to provide the required electromagnetic force across a solenoid coil to actuate a valve.
Supervisory circuit loops are also known in the prior art. In known supervisory circuit loops a resistor is utilized in the supervisory circuit loop which provides a current drain. This is acceptable where the supervisory circuit loop is powered by line current but is unacceptable when a small battery is utilized to power the supervisory circuit loop and long life is expected.
The present invention provides a new and improved system for actuating an electric valve from a remote location which utilizes a battery to power the system and which includes a capacitor as the supervisory element rather than a resistor in a supervisory circuit loop to minimize current drain from the battery. The capacitor provides for higher security when used in the supervisory circuit loop than a resistor because a resistor can be easily measured by an ohm meter.